Elusive Dwarf Octopuses Hatch in Captivity

Katherine Harmon Courage is a freelance writer and contributing editor for Scientific American. Her book Octopus! The Most Mysterious Creature In the Sea is out now from Penguin/Current. Follow on Twitter @KHCourage.

Katherine Harmon Courage is a freelance writer and contributing editor for Scientific American. Her book Octopus! The Most Mysterious Creature In the Sea is out now from Penguin/Current. Follow on Twitter @KHCourage.

In the dark of night, between Monday, March 17, and Tuesday, March 18, dozens of fully formed baby octopuses burst forth from their outsized eggs.

It seems only natural that these octopuses would begin their life under the cover of darkness. These baby Caribbean dwarf octopuses (Octopus mercatoris) come from an elusive family of octopods that are difficult to track down—even in captivity. Aside from their petite stature, they are also nocturnal and expert hiders, which keeps them safe from predators but often out of our sight as well.

Given this cryptic behavior, the Mote Marine Laboratory’s aquarium in Sarasota, Fla., where the octopuses hatched, has decided not to try to display them to the public yet. But their cephalopod specialist Brian Siegel is currently looking into the best way to show off these and other nocturnal (or otherwise shy) ceph species.

The babies came from a female that had been captured off the coast of Florida near the lab. The female had apparently already mated before she arrived at the aquarium, because the eggs she laid proved to be viable.

These young dwarf octopuses might seem small—and, compared to objects on our human scale, they are. But they are also a rarity among octopuses. Most octopus species lay thousands upon thousands of tiny eggs. But this octopus laid just 50 or so in her brood. And each egg measured in at roughly a quarter inch long—relatively large for an octopus that, itself, reaches a length of just an inch and a half or so.

As with other octopuses that come from small broods of big eggs, these babies took a long time to develop—some two months. But when they hatched, unlike most octopus species that start life as larvae, these octopuses already looked like mini adults.

Siegel is also hoping to establish a program to rear these dwarf octopuses to supply other research institutions and aquariums.

About the Author: Katherine Harmon Courage is a freelance writer and contributing editor for Scientific American. Her book Octopus! The Most Mysterious Creature In the Sea is out now from Penguin/Current. Follow on Twitter @KHCourage.